Record numbers of gay men and lesbians, whose sexuality is neither a secret nor a source of controversy, occupy key positions across British life. They influence the entertainment we consume, how safe our streets are, the quality of our hospitals, how well solicitors perform, the country's political direction and much else besides.

They are doers, decision-makers, entrepreneurs, administrators and definers of taste. They wield real power. They run companies worth billions of pounds as well as key public service organisations. They all have an impact on our daily lives or the world around us, through their decisions, attitudes, tastes and priorities.

With this week's first civil partnerships representing a milestone in gay equality, The Observer celebrates, in no particular order, 20 of the most influential gays and lesbians who are helping to shape and change the 21st-century Britain in which we all live. Janet Paraskeva, Law Society chief executive and one of the 20, says highlighting gays and lesbians in influential positions who are open about their sexuality could give others the courage to come out.

There are three people we wanted to list: the chief executive of a major FTSE 100 company, one of Britain's leading sportspeople and a senior government adviser. Significantly, none has 'come out', so they are not included. The climate may indeed be more tolerant, but clearly not tolerant enough.

Janet Paraskeva Age: 59 Chief executive of the Law Society

Runs the organisation which represents and regulates the 121,165 solicitors in England and Wales. First to take on the newly created role of Law Society chief executive in 2000, at which time the Independent asked 'Is this the worst job in the country?', because the lawyers' professional body was underperforming and beset with claims of sexual and racial discrimination and bullying of staff. Has restored order and is pushing through a radical and, critics say, long overdue modernisation which will split the society into three divisions: consumer complaints, regulation and professional services.

Born in Newport, Gwent, Paraskeva intends to take advantage of the Civil Partnerships Act to 'marry' her partner of more than a decade, whom she will only refer to as 'Mary'. She prefers not to give Mary's surname and will only say that 'she works in education'.

'We haven't decided when, but we are pretty likely to do it,' says Paraskeva. 'The children [Paraskeva has two children from a previous marriage] keep nagging us. I think they just want the party.'

Paraskeva is also involved with ChildLine, Ofsted and the British Youth Council. Intends to retire in 2006 when Law Society restructuring is complete and take on portfolio of parttime roles. Already a non-executive director of the new Serious Organised Crime Squad and the Consumer Council for Water.

Russell T Davies Age: 42 Scriptwriter

Head writer of the BBC's recently revived Doctor Who. Also responsible for other audience-pullers such as Casanova, Linda Green and Bob & Rose. Came to prominence in 1999 when Channel 4 showed his controversial drama series Queer as Folk, an explicit tableau of love, lust, clubbing and gay life in Manchester. Currently working on the Doctor Who spin-off series, Torchwood, about a team who investigate alien goings-on in Britain, due to be aired on BBC3 in 2006 - 'X Files meets This Life,' says Davies. Has been with his partner, Andrew Smith, a Customs officer, since 1999. Born in Swansea.

Britain's most outspoken police officer is now in charge of 'territorial policing' (street crime, burglary and sexual offences) across the capital. Dubbed 'Commander Crackpot' by some papers when he pioneered a 'softly, softly' approach to cannabis possession as borough commander in Lambeth, south London, Paddick has admitted that he found the idea of anarchism appealing. Plans to retire late next year, after 30 years in the Met, and seek a new career in politics, campaigning or the media.

Angela Mason Age: 61 Government adviser on women's and equality issues Director of the Women and Equality Unit, a team of 35 civil servants at the Department of Trade and Industry. It handles government policy on issues such as civil partnerships, the gender pay gap, the current Equality Bill and controversial moves to create a new, unified Commission for Equality and Human Rights. Former executive director of gay rights group Stonewall, where she campaigned on repealing Section 28, homophobic bullying and legal rights for gay and lesbian couples. CV includes stints with Women's Aid, the London Law centres, the trade union movement and as principal solicitor for the London Borough of Camden.

Awarded the OBE 'for services to homosexual rights' in the Queen's birthday honours in 1999. Grew up on the Isle of Sheppey. Was briefly married in the 1970s. Had a daughter by artificial insemination in 1985.

'A Sapphic Mrs Pepperpot, a stoic little 56-year-old with a grim and polite determination [whose] quiet, intense political lobbying [has] made Stonewall one of the most astoundingly successful lobby groups in Britain in terms of objectives achieved.' - Euan Ferguson, The Observer, 2000

Nick Partridge Age: 50 HIV and Aids campaigner

Has worked for the Terrence Higgins Trust, the country's leading HIV and Aids organisation, since the mid-1980s, and since 1991 has been chief executive. Lobbied for and secured countless advances in areas such as the treatment of HIV sufferers with drugs, social care, and public health education. Articulate media performer.

Awarded the OBE in 1999 for services to charity and the lifetime achievement award in the UK Charity Awards in 2002. He is also a commissioner with the Healthcare Commission, which inspects and awards ratings to hospitals, and chairman of Involve, which promotes greater public involvement in the NHS.

Jasper Conran Age: 46 Fashion designer

Son of the designer Terence and the author Shirley, who split up when he was two, Conran is now taking on high street mass market fashion with ranges of clothing for Debenhams, where one aim is to make more stylish garments for older women. Enrolled at Parsons School of Design in New York at 16. Was briefly married to Jeannie Spaziani, a fellow pupil. Returned to London to start his career. Vogue gave his second collection 10 pages of coverage when he was just 19.

'I don't think anybody should go around working out what someone's sexuality is or is not. I don't think you can define what gay is, or straight is, or bisexual is. It's just who people are and what they do at a given time' - Jasper Conran, The Times, 2005

Runs the Arts Council's London office. Influential arts funder: her organisation spends £120 million a year supporting everything from major cultural institutions, such as the National Theatre, Royal Opera House and the capital's symphony orchestras, to grassroots arts projects. In charge of 120 staff. Former City high-flyer who earned big money during 15 years in the Lloyd's insurance market, then abandoned her sports-car-and-champagne lifestyle in order to break into the arts, which were and remain 'her obsession', say friends. Touted as potential next chief executive of the Arts Council.

Dawn Airey Age: 45 Television executive

Managing director of Sky Networks at BSkyB. One of the most powerful women in TV, and certainly the bestpaid: earns a reputed £1m a year. In charge of a portfolio of channels at Rupert Murdoch's satellite broadcaster including Sky One, Sky News, Sky Movies and Sky Travel. Became Executive Chair of the Guardian Edinburgh International Television Festival in 2003. Born in Preston. Lived with partner Martin Pearce for 19 years. Rejected by the BBC as a graduate trainee. Began broadcasting career at Central TV, then moved into senior jobs at ITV and Channel 4. Became boss of Channel 5, where the ratings went up thanks to what Airey joked were 'the three Fs - films, fucking and football'. Fought over by ITV and Sky before joining the latter. A non-executive director of Easyjet and on ActionAid's board of trustees.

'The most talked-about woman in television. A skilful manipulator of public taste' - Mail on Sunday, 2002

Maureen Chadwick Age: 52 Scriptwriter

Lead writer with Shed Productions, the Zeitgeist-defining and highly successful company behind hit shows such as Bad Girls and Footballers' Wives. Helped set up Shed in 1998 with three friends with whom she had worked at Granada TV: Eileen Gallagher, Ann McManus and Brian Park. Shed has been criticised for its often risqué content, but she defended what some saw as Bad Girls sensationalising life in women's jails, claiming it helped to expose realities such as bullying, sexual harassment and drug-taking.

Very publicity-shy; leaves PR duties to Gallagher. 'Works closely with Ann McManus to create stories and characters and develop every episode from master scene storyline to shooting script,' says her sparse Shed biography. Has also written episodes of EastEnders and Coronation Street, and original scripts for theatre and musical theatre.

expose realities such as bullying, sexual harassment and drug-taking. Very publicity-shy; leaves PR duties to Gallagher. 'Works closely with Ann McManus to create stories and characters and develop every episode from master scene storyline to shooting script,' says her sparse Shed biography. Has also written episodes of EastEnders and Coronation Street, and original scripts for theatre and musical theatre.

Ben Summerskill Age: 44 Chief executive of Stonewall

Transformed the gay equality campaign group since taking over in early 2003. Has made it assiduously crossparty and built on contacts from a 12- year journalistic career including stints at The Observer, Daily Express and Evening Standard. Ex-editor of the Pink Paper. Quietly effective lobbyist to whom most doors in the corridors of power are open. Has helped persuade a hostile House of Lords to back four key legislative changes such as heavier sentences for anti-gay hate crimes, civil partnerships and repeal of Section 28. There are now 145 companies and governmental bodies in Stonewall's workplace programme, such as IBM, Barclays and the Royal Navy. Tipped to become chief executive of the new Commission for Equality and Human Rights.

Increasingly influential member of Gordon Brown's inner circle of young, brainy and ultra-loyal aides, which includes Ed Balls and Ed Miliband, who are both now MPs. The relationship is described as one of 'complete trust' and Spencer sees all policy documents that cross the Chancellor's desk.

Destined for a pivotal role at Number 10, such as head of the Downing Street policy unit, if and when Brown replaces Tony Blair. Born in Slough but brought up in Essex. Read economics and politics at the LSE before joining the Labour Party's economic research unit in 1997, which started his dramatic rise up the political ladder. Became Brown's chief adviser after last May's general election. 'He's brilliantly clever, but also very engaging and charming - a good contrast to Gordon, who's always very intense,' says a friend. Loves music: wears an iPod on the Tube on his way into work. Keen film fan and supports Fulham FC.

Neil Wooding Age: 45 Senior civil servant

Director of Public Service Management in Wales with the Welsh Assembly. Leads a team of specialist advisers who work to build management and leadership skills and improve policy co-ordination, across the entire public sector in Wales. Also works three days a month as the Equal Opportunities Commissioner for Wales, charged with 'ensuring the equal treatment of men and women in all spheres of public life'.

Ex-director of the NHS Centre for Equality and Human Rights. Is also a board member and trustee of the National Aids Trust, co-chair of Stonewall Cymru, vice-president of the Welsh Food Alliance and a fellow of the National Centre for Public Policy. Leading campaigner on gay issues in Wales, such as making workplaces more welcoming to gay staff.

Nicholas Hytner Age 49 Director of the National Theatre

NT director since 2003, Hytner has directed dozens of theatre and opera productions since 1985. The Madness of King George in 1994 marked his debut behind the camera, and won the Bafta award for Best British Film. He has scooped an array of Best Director awards, including a Tony, and at the Olivier, Critics Circle and Evening Standard awards. Born in Manchester.

Cut his teeth at the city's vibrant Royal Exchange Theatre. Other film credits include The Object of My Affection and The Crucible. Brother Jim is marketing director of Barclays Bank.

Andre Graham Age: 44 Entrepreneur

Northern Ireland's most prominent gay man, Graham is a New Zealander who lives in Belfast, where he has become a millionaire by creating a 'gay quarter' near St Anne's Cathedral. His partner in both business and life is 33-year-old Seamus Sweeney.

They jointly own venues such as the Kremlin, Northern Ireland's first official gay bar; the Union Street Bar and Restaurant; and the Garage sauna, the country's only gay sauna. Former chief executive officer of Sony PlayStation in 35 countries, Graham retired at 35. He liaises with the Police Service of Northern Ireland to try to keep customers of premises in the 'gay quarter' safe from homophobic attacks. He and Sweeney plan to marry in a civil partnership in 2006.

Margaret Smith Age: 44 Member of the Scottish Parliament

Chief whip of the Liberal Democrat group at Holyrood. MSP for Edinburgh West. 'Outed' herself in May 2003 before a Sunday tabloid did so, saying: 'I am very happy to confirm that I am in a relationship with a female partner.

My family are being very supportive.' One of three openly gay members among the 129 MSPs, alongside fellow Lib Dem Iain Smith and Patrick Harvie of the Greens. Campaigns on health issues, and gay and lesbian rights. Was married, but separated from her husband in 2000 and is now divorced. Has a son and daughter.

Nicholas Bloles Age: 40 Adviser to David Cameron

Director of the Policy Exchange think-tank, which is a networking club for young Tory modernisers, many of whom are 'Cameroons'. He is the second gay person to become an aide to Cameron, alongside the newly appointed party vice-chairman Margot James.

Boles is close to party chairman Francis Maude, who is now embarking on Cameron-directed major reforms to the Tories' image, candidate selection and annual conference location. Tipped to get a safe seat at next election, if not before. Remains non-executive chairman of Longwall Holdings, which supplies the DIY industry, which he set up in 1995. Is also interested in the arts; in 2002 he was associate producer of a production of The Mysteries in the West End.

Ali Smith Age: 43 Writer/novelist

Her last two novels both made the Booker shortlist - Hotel World in 2001 and The Accidental this year. She is on the shortlist for next month's Whitbread award and enjoying rising sales.

Brought up on a council estate in Inverness by her electrician father and bus conductor mother, she learnt to read aged three by studying the labels on her older siblings' collections of singles. Lives with her partner Sarah, a film-maker, in Cambridge. Initially worked as an academic before Virago published her first collection, Free Love and Other Stories, in 1995 and she became a full-time writer. Sparked a row about the quality of women's writing earlier this year when, as co-editor of a British Council anthology of new writing, she lamented that 'the submissions from women were disappointingly domestic'.

Charles Allen Age: 48 ITV chief executive

Head of the commercial TV giant formed by the merger between Granada and Carlton. His in-tray includes how to reverse ITV's falling audience share and handle widely expected takeover bids. Survived the disastrous £1.2 billion failure of ITV Digital, and ex- BSkyB chief executive Tony Ball saying that Allen couldn't 'run a bath'.

Oversaw ITV's recent £175m purchase of Friends Reunited. Played a key role in ensuring that the 2002 Commonwealth Games in Manchester were a success, and repeated the trick with London's bid for the 2012 Olympics.

Comes from a working-class family in Bellshill, Lanarkshire and is dyslexic. His hairdresser father died at 14, forcing his mother to work as a waitress to look after her three children. Has a long-term partner. He was made a CBE in 2003 and is considered a likely future Labour peer.

Cameron Mackintosh Age: 59 Theatre impresario

Key figure in London theatreland who is worth an estimated £400m. With Andrew Lloyd Webber, Mackintosh helped turn musicals into blockbusters - working on Cats, Phantom of the Opera, Miss Saigon and Les Misérables. Now owns six London theatres - the Prince Edward, Prince of Wales, Strand, Gielgud, Wyndhams and Albery. Missed out on university because his exam results were too poor. Became a stagehand, then an assistant stage manager and then a producer. Lives with his long-term partner, the photographer Michael Le Poer Trench. Mackintosh has homes in London and in New York, Scotland, Provence and Somerset.

Andrew Pierce Age: 44 Journalist

His title, assistant editor at the Times, barely does justice to his contribution to the Thunderer: story-getting, patrolling Westminster and Whitehall, and supplying gossipy diary items. Well connected in royal circles and with the Conservatives. Recently exchanged doing the Times Diary for a return to the parliamentary lobby, which he loves. Currently tipped to replace Boris Johnson as editor of the Spectator.

'Gay gadfly from Swindon's best council estate' - The Independent, June 2005